Absorption properties of iron nitrides particles fabricated by ball milling

Iron nitrides particles with about 50% γ′-Fe4N phase have been fabricated by traditional gas nitriding method and ball milling technique. Diameter of the particles is in a large range, from 5µm to 50µm. The electromagnetic wave absorption properties of the iron nitrides particles were investigated in the frequency range from 12.4GHz to 18GHz. The frequency range of reflection loss exceeding −20dB was 12.4 – 18GHz, and the thickness range of absorber for that was 1.41 – 2.31mm. An optimal reflection loss of −27.12dB was reached at the frequency of 15.5GHz with the thickness was 1.72mm. As a result, these iron nitrides particles could be applied in practical electromagnetic wave absorbing.